RT34063A
8
1
+
V
OUT
7
V
IN
2
6
3
5
4
(a) External NPN Switch
8
1
R
+
V
OUT
7
V
IN
2
R
0 for
Constant VIN
6
3
5
4
(b) External NPN Saturated Switch (See Note)
Figure 2. External Current Boost Connections for I
C
Peak Greater than 1.5A
Note: If the output switch is driven into hard saturation (non-Darlington configuration) at low switch currents (
≤
300mA) and
high driver currents ( 30mA), it may take up to 2.0μs to come out of saturation. This condition will shorten the off time at
≥
frequencies
≥
30kHz, and is magnified at high temperature. This condition does not occur with a Darlington configuration,
since the output switch cannot saturate. If a non-Darlington configuration is used, the following output drive condition is
recommended.
DS34063A-13 March 2007
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